i agree this is a hard thing to do and sorry to be so the original poster. My list is the 20 that I would to pick from to compose an dream :
Centers: Wilt, Kareem, Russell, Shaq, D. Robinson, and the Dream (6)
Forwards: , Bird, K. Malone, LeBron, Baylor, Barkley, Garnett (7)
Guards: Jordan, Magic, West, Kobe, Oscar, Wade, Cousy (7)
Hardest to leave off: Havlicek, Pe , and Lucas. I also believe that Kidd, Stockton and Nash are all somewhat under-appreciated for their greatness and could all deserve to be on the list. Durant when he has another couple of great years - will have to replace someone on the top 20 - leaving probably a hard pick between D. Robinson, Barkley or Garnett.